Guys, I used to own a Roland MC-50 MKii and now I have a Roland PMA-5. But they are both too old and hard to use. So I was thinking on doing my own MIDI Sequencer with the Arduino. But the thing is, I can't figure out if the Arduino speed and memory will be enough for a project like this. I was hoping to have multiple-midi-tracks, Midi In and Out.

I'm used to C++, so that's not a problem. ;-) I just worry the memory usage. Maybe I could keep all the buffers in code and just use an external SD card for storage. (Save/Load) Or something like that.

I saw the EEprom modules, but they are expensive, and I think a SD card would be better, as I could backup files to my computer if I wanted to.

Yes this would work. Yes you would be better off using an SD card to store things on.Lots of MIDI projects about but I have not seen anything like this, but it shouldn't be too hard, but you will probably end up writing it yourself. So if you know nothing start on something more simple.

What MIDI file format do you want to support? Type 1 (or is that type 0) would be the best for this application.

Thanks bud. I'm not actually looking into a .mid format, but rather my own format, as this will be a multi-track sequencer, and not a midi-player. Of course, with time I could make it export .mid files.

I'm getting the Arduino MEGA, so I have more memory and more I/Os for other things, that I plan on using on another project. ;-)

And yes, SD looks the way to go, I'm already aware of the memory limitations of the Arduino.